Interval timer



July 28, 1953 R. c. DARNELL 6 6,84

INTERVAL TIMER Filed Sept. 29, 1951 2 2 Sheetg-Sheet 1 INVENTOR. Fax

/77' arrlvsr R. C- DARNELL July 28, 1953 INTERVAL TIMER 2 Sheets-Sheet 2 Filed Sept. 29, 1951 INVENTOR. if! azar/yeZZ.

BY M M YA flI70/7/VEV5,

Patented July 28, 1953 INTERVAL TIMER Rex C. Darnell, Dexter, Mich., assignor to King- Seeley Corporation, Ann Arbor, Mich., a corporation of Michigan Application September 29, 1951, Serial No. 249,699

'7 Claims. 1

The present invention relates to an improved interval timer and more particularly to an improved interval timer of the type including a signal actuating member mounted for movement between cocked and tripped positions and including a cam element adapted to move the signal actuating member to its cocked position, and a latch element adapted to engage the signal actuating member and hold it in the cooked position.

It is an object of the present invention to provide an improved interval timer of the above mentioned type which is simplified in design, reliable and efficient in operation and economical of manufacture. More particularly, it is an object of the present invention to provide such an improved interval timer construction in which the cam element is mounted on the timer arbor by an improved construction as a result of which the cam has an eiiective height of a predetermined amount during rotation of the arbor in a winding or cooking direction while upon rotation of the arbor in the opposite or tripping direction the cam has a lesser effective height, and whereby upon rotation of the arbor in a cooking direction the cam is effective to move the signal actuating member to its cocked position and during return movement of the arbor in a tripping direction the high point of the cam is at a lesser height, thereby preventing interference of the high point of the cam with the signal actuating member.

It is a furtherobject of the present invention to provide an improved interval timer construction of the above mentioned type wherein the arbor and the cam have co-operating means effective upon rotation of the arbor in one direction for connecting the cam to the arbor for rotation abut a given axis relative to the cam, and which is effective upon rotation of the arbor in the opposite direction for connecting the cam to the arbor for rotation about a second axis relative to the cam which is spaced from the first mentioned axis.

Another object of the present invention is to moved transversely of the arbor upon reversal of the direction of rotation of the arbor.

Other and more detailed objects of the present invention will be apparent from a consideraclaims and accompanying drawings wherein:

Figure 1 is an elevational view taken from one side of the timer mechanism with the housing and bell removed;

Figure 2 is a sectional View taken along the line 2-2 of Figure 1;

Figure 3 is an elevational view looking at the timer from the opposite side to that shown in Figure 1; and,

Figure 4 is an enlarged broken sectional view or" the structure illustrated in Figure 2 taken substantially along the line 44 thereof.

Many of the features of construction of the timer illustrated in the accompanying drawings are of a generally conventional design and only so much of the construction is illustrated and described in detail herein as is necessary for a full understanding of the features of the present invention. The interval timer to which the present invention relates, and which is shown in the accompanying drawings, is of the type inwhich the main arbor of the clockwork is provided with a manual control knob (not shown) and the construction and arrangement is such that when the arbor is rotated in one direction from a zero or starting position the signal actuator is cooked. The rate of return of the arbor to the starting position is controlled by the clock mechanism and the signal actuator is tripped upon return of the arbor to the starting position, thus operating a suitable signal.

Referring to the drawings, the present invention is shown incorporated in a timer having a clock mechanism carried by and between a pair of movement plates 0 and I2. The clock mecha-- nism includes a main arbor l4 suitably journaled in the movement plates and connected in the usual manner through a train of gears to a verge-type escapement comprising an escape wheel 16, a verge arm [8, and a balance Wheel 20 carried by a balance staff 22. The ends of the balance staff 22 are tapered and fitted into conical bearings 24 and 26 mounted respectively in the movement plates [0 and I2. A main spring 29 is mounted on the outer side of the movement plate It), as best illustrated in Figures 1 and 2, and has its outer end anchored to an outwardly turned projection 30 on the movement plate [0 (see Figure 1) and has its inner end connected to the arbor [4 as illustrated in Figures 1 and 2, by means of a spring anchor plate 32.

It will be appreciated that the spring 23 normally tends to rotate the arbor 14 in a countertion of the following specification, the appended clockwise direction as viewed in Figure 1 and in a clockwise direction as viewed in Figures 3 and 4, under the control of the escapement mechanism and associated-gear train in the usual manner.

In the preferred embodiment illustrated in the drawings, the mechanism of the timer which operates the signal comprises a short stub shaft 34 secured to the movement plate 12 and on which is journaled a hammer bell cranl; 36, the shape of which is best illustrated in Figure 3. The bell crank 36 includes an outer arm portion 38 adapted to engage a suitable signal device which in the preferred embodiment illustrated the drawings is the bell indicated at 40, and an inner arm 42 having an outwardly turned projection 44 extending outwardly through an Opening 46 provided in the movement plate [2. A spring 48 is mounted on the plate H as indicated at 50 and engages an outwardly turned projection 52 on the outer arm 38 of the signal actuator 86, which projection 52 extends outwardly through an opening 54 provided in the movement plate 2. The movement plate 12 is also provided with an outwardly turned projection 56 engaged by the spring 48 in the position of rest to which the signal actuator 36 comes after it is tripped.

The cocking and tripping mechanism comprises a latch 58 which is pivotally mounted on the movement plate 12 by a rivet 66 and is provided with a latching portion 62 adapted to move under the outwardly extending projection 44 on the signal actuator or hammer 36 to hold the hammer 36 in the cocked position. The latch 58 is ur ed in a counterclockwise direction as viewed in Figure 3, by a spring 64, one end of which is mounted in the movement plate 12 as indicated at $6 and the other end of which ongages an outwardly turned projection 68 on the latch 53. A cam plate 76 is mounted on the arbor l4 and is drivingly connected thereto as hereinafter described for en aging the projection of the hammer 3!; and pivotaliy moving the hammer 36 in a counterclockwise direction as viewed in Figure 3, to a position in which the spring 6.6 acting against the latch 58 may move the latching portion 62 of the latter into position to engage the projection 44 on the hammer and hold the hammer in cocked POSi-tion. For this purpose the cam plate It is provided with a cam surface 12. The portion of the arbor i4 upon which the cam plate is mounted provided with a pair of opposed parallel flats 14, best illustrated in Figures 2 and 4. The cam plate 7% is provided with a central opening generally indicated at 16 receiving the portion of the arbor i4 having the flats 14. This opening 16 is adapted to provide a lost motion connection between the arbor i4 and the cam plate 10 and provide a, driving connection between the arbor and the cam plate Tilt; affording an ef ective height of the cam surface 12, upon rotation of the arbor in a winding or setting direction (;a clockwise direction as viewed in Figure ,3) which is sufficient to move the hammer .36 a counterclockwise direction :as viewed in Figure 3 to its cocked position in which the latching portion 2 of the latch 53 may be moved into engagement with the projection :44 by the .54. Also the shape .of the opening 16 is such that pon rotation of the arbor 4.4 in the opposite .di rection, as during the return movement of the arbor to the starting or zero position under the control of the escapement mechanism, the cam plate 10 is connected to the arbor I4 and driven thereby with the cam surface 12 having alesser efiec'tive height than durin rotation of the ar o in the other direction so that during such return movement the cam plate H1 does not interfere with the projection 44 on the hammer 36. The cam plate 10 is, however, provided with an inwardly turned projection I8 which engages a co-operating outwardly turned projection 86 on the latch plate 58 to pivot the latch plate 58 in a clockwise direction as viewed in Figure 3 and move. the latc n portion 3 out 9i a ement with the projection 44, thereby tripping the hammer 36 and permitting the spring 48 to throw the outer arm portion 38 of the hammer 36 outwardly against the skirt of the bell 40.

In the preferred embodiment illustrated the opening 16 provided in the cam plate 10 includes a pair of diverging flat side walls 82 and 84, a curved end wall 86 interconnecting the closer ends of the diverging side walls 82 and 84 and adapted to fit the curved portion of the arbor when one of the flats 14 thereof is disposed in substantial alignment with the fiat side wall 82.

The opposite ends f the side walls 82 and 84 are inter-connected by a curved end wall 88 including a portion adjacent the side wall 84 adapted to fit the curved surface of the arbor when the other flat [4 thereof is disposed in substantial alignment with the side wall B4, 'The shape of this opening is clearly illustrated in Figure 4. It will be appreciated that the lost motion connection between the cam plate 10 and the arbor 14 above described permits the cam plate E6 to move transversely relative to the arbor 14 when the direction of rotation of the arbor i4 is reversed, thereby affording the two different effective heights of the cam surface 12 described above.

Figure 4 illustrates in full lines the relative positions of the cam plate 19 and the arbor !4 during the driving of the cam plate '10 by the arbor l4 while the latter is being returned toward the starting position under the influence of the cam spring 28 and the control of the escapement mechanism. It will be noted that in this position the arbor engages the cam plate "H3 on the side 84 at the point indicated by the numeral 94, on the side 82 at the point indicated by the numeral 96. It will be appreciated that there may be a slight movement of the cam plate "lil relative to the arbor l4 so that the arbor i4 may engage either the curved surface 86 or the curved surface 88 when in the position illustrated in Figure 4. During rotation of the arbor I4 in the opposite or winding direction, or counterclockwise direction as viewed in Figures 3 and 4, the position of the arbor 14 relative to the cam in is illustrated in broken lines in Figure 4 in which it will be noted that one of the flats 14 is in engagement with the cam 18 at the flat side 62 of the opening 16 and the curved portion of the arbor at one end of the flats "I4 is in engagement with the curved end wall 86, and the arbor 14 at the juncture of the opposite flat I4 and the curved surface engaging the curved end wall engages the cam 'platalil at the juncture of the flat side '84 and the curved end wall '86.

The signal actuator '35 carries a spring secured thereto as indicated at 92, the outer end of which engages the balance stafi '22 when the signal actuator 36 is tripped. The engagement of the spring 89 with the balance staff 22 provides a frictional drag on the balance staff 22 stopping the latter, thereby providing a -zero stop for the timer mechanism. The mounting 92 of the spring -90 on the hammer 36 is so disposed relative to the shaft 34 upon which the signal actuator 36 is mounted that the loading of the spring resulting from the engagement 6f the outer end of the spring with the balance staif 22 urges the signal actuator 36 in a counterclockwise direction. This feature forms no part of the present invention and is illustrated and described in greater detail and claimed in the copending application of Kenneth M. Kiel, Serial No. 248,935, filed September 29, 1951. As a result of this construction the spring 9!! both functions as a zero stop means and als functions as a means for returning the hammer 36 from engagement with the bell 40.

While only one preferred embodiment of the present invention has been illustrated and described herein it will be readily appreciated by those skilled in the art that numerous modifications and changes may be made without departing from the spirit of the present invention.

What is claimed is:

1.. In an interval timer, an arbor rotatable in one direction from a zero position for setting the interval to be timed. means for returning the arbor to the zero position upon the expiration of the interval for which the timer is set, a signal actuating member movable between first and second positions, means urging said member toward said second position, a cam mounted on said arbor for moving said member to said first position, and a latch element engageable with said member for holding said member in said first position, said cam and said arbor having cooperating means effective upon rotation of said arbor in one direction to connect said cam to said arbor for rotation about one axis relative to said cam and effective upon rotation of said arbor in the opposite direction to connect said cam to said arbor for rotation about a second axis relative to said cam spaced from said axis.

2. In an interval timer, an arbor rotatable in one direction from a zero position for setting the interval to be timed, means for returning the arbor to the zero position upon the expiration of the interval for which the timer is set, a signal actuating member movable between first and second positions, means urging said member toward said second position, a cam mounted on said arbor for moving said member to said first position, and a latch element engageable with said member for holding said member in said first position, said cam and said arbor having cooperating means effective upon rotation of said arbor in one direction to connect said cam to said arbor to provide a predetermined height of said cam and eiifective upon rotation of said arbor in the opposite direction to connect said cam to said arbor to provide a lesser cam height so that upon said rotation in said opposite direction said cam will not engage said member.

3. The combination as defined in claim 1, wherein said co-operating means is also effective, upon reversal of the direction of rotation of said arbor to move said cam transversely of said arbor from a position in which one of said axes coincides with the axis of said arbor to a position in which the other of said axes coincides with the axis of said arbor.

4. In an interval timer, an arbor rotatable in one direction from a zero position for setting the interval to be timed, means for returning the arbor to the zero position upon the expiration of the interval for which the timer is set, a signal actuating member movable between first and secand positions, means urging said member toward said second position, a cam mounted on said arbor for moving said member to said first position, and a latch element engageable with said member for holding said member in said first position, said arbor having a noncircular portion,

and said cam being mounted on said arbor for engagement with said noncircular portion thereof and having an aperture receiving and substantially larger than said portion of said arbor to provide a 10st motion connection between said cam and said arbor effective upon rotation of said arbor in one direction to provide a predetermined height of said cam and effective upon rotation of said arbor in the opposite direction to provide a lesser cam height.

5. The combination as defined in claim 4, wherein one portion of said aperture receives and is substantially equal to the width of said portion of said arbor at one side thereof and the opposite portion of said aperture receives and is substantially wider than the width of the opposite side of said portion of said arbor.

6. In an interval timer, an arbor rotatable in one direction from a zero posiiton for setting the interval to be timed, means for returning the arbor to the zero position upon the expiration of the interval for which the timer is set, a signal actuating member movable between first and second positions, means urging said member toward said second position, a cam mounted on said arbor for moving said member to said first position, and a latch element engageable with said member for holding said member in said first position, said arbor having a pair of opposed flats on one portion thereof and said cam defining an opening receiving said portion of said arbor and bounded by a pair of diverging side walls adapted to engage and slightly longer than the adjacent flats on said arbor and arcuate end walls interconnecting the adjacent ends of said side walls.

7. The combination as defined in claim 6, wherein said arbor is generally of circular cross section, the shorter of said arcuate end walls has a radius of curvature substantially equal to that of said arbor and is disposed to substantially fit the curved surface of said arbor when one of said flats of said arbor is aligned with one of said diverging side walls, and the other of said end walls includes a first portion adjacent said one of said diverging side walls which has a radius of curvature substantially equal to the diameter of said arbor and a second portion adjacent the other of said side walls and forming a continuation of said first portion which has a radius of curvature substantially equal to that of said arbor and is disposed to substantially fit the curved surface of said arbor when the other of said flats of said arbor is aligned with the other of said side walls.

REX C. DARNELL.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,150,633 Rhodes Mar. 14, 1939 2,258,474 Simmons Oct. 7, 1941 2,543,032 Laviana Feb. 27, 1951 

